1433 Inter-blink tear film dioptric power changes can explain contrast sensitivity modifications in normal and keratoconjunctivitis sicca eyes

b one of the main early complaints of cataract patients, even when they exhibit only mild glare. problems as measured by standard tests. is that alare impairs their night driving In order to better measure the patients’~mpair&nt, glare tes?s shouldhclude measurements of the alam effect in conditions more similar to those found in night driving. iirhen driving at night the ambient light is very low, onc&ng headlights present a transient temporal pattern, and the objects of interest often appear initially in the peripheral visual field. Thus, three impottant characteristics of glare in night driving am that the ambient illuminance is in the scotopic/mesopic range, the detection stimulus is in the periphery, and the glare source is transient. Most of the current glare testers measure glare only at photopic levels, and all the glare tests that we know of use only steady smuces of glare with foveal discriminations. We studied all three conditions. Methods: Detection stimuli were presented on a computer monitor, and the glare source was a high-intensity hmgsten bulb. Stimuli were presented at different times following the sudden onset of glare, in the fovea and peripheral visual field. Results: Disability glare effects are stronger in the periphery than in the fovea. The difference between the transient glare effect and the steady glare effect is greater in the periphery than in the fovea. The duration of the transient effect is also longer in the periphery than in the fovea, an: the recovery time from glare is longer in the periphery. Conclusions: Transient glare effects, such as those often encountered in real world, are much stronger than those tested with a steady glare ~muce in the fovea, and even more so in the periphery. Existing glare testers seriously underestimate disability glare effects in everyday life.